This invention relates to exercise weights and, in particular, to a weight of variable heaviness adapted for use on either the hands or feet during aerobic exercises.
During the past several years it has become apparent that the use of light weights during aerobic exercise will enhance body development and greatly increase the benefit to the cardiovascular system. The preferred amount of weight will vary with the physical condition of the individual and with the particular exercise being performed.
Dumbbells, which are basically comprised of a handgrip with a weight attached to each end, have been adapted for use as hand weights for aerobic exercise. See U.S. Pat. No. 4,351,526. However, the heaviness of such dumbbells can only be varied by changing the weights. Thus, a person whose physical condition is changing or who wishes to perform different exercises must have a variety of weights available to him.
Dumbbells have the further disadvantage of concentrating the weight at either end of the handgrip. When materials of relatively low density are used in such a configuration, the increased length of the device will increase the torque on the hand and wrist during exercise. The muscular fatigue induced by such torque will tend to limit the duration, and, hence, the aerobic benefit, of the exercise. This effect is particularly pronounced where, as is described in U.S. Pat. No. 4,076,236, additional weights consisting of hollow bodies containing materials of relatively low density are added to either end of the dumbbells.
In other variable weight exercise devices, such as that described in U.S. Pat. No. 4,079,932, the center of gravity is actually located distal to the hand. This configuration also tends to subject the hand and wrist to relatively high torques.
The devices described above are suitable only as hand weights. Other devices have been designed to variably weight the foot. E.g. U.S. Pat. Nos. 4,322,072; 1,990,970. Devices in the latter class are not, however, adapted for use as hand weights.